NEW YORK (CNNMoney.com) -- Prices of most major commodities stayed mixed Wednesday, even after the Fed announced a $600 billion asset purchase plan.
Commodities have been on a tear since late August, when Federal Reserve chairman Ben Bernanke said the central bank would take "unconventional measures" to keep the economy afloat.
The speculation ended with the Fed's statement Wednesday afternoon, in which the central bank said it will buy $600 billion of longer-term Treasuries by the end of the second quarter of 2011.
These asset purchases, known as quantitative easing, are designed to boost the economy and lower interest rates.
But all the talk about quantitative easing in the past few months has put pressure on an already weak U.S. dollar, which affects commodities because they are priced in dollars around the world. A lower greenback makes it cheaper for foreign investors to buy commodities.
Still, the Fed statement didn't have much an effect on commodity prices Wednesday. Crude oil for December delivery rose 0.9% to settle at $84.69 a barrel, but the major metals were sharply lower. Gold slid 1.4% to settle at $1,337.60 an ounce.
Crude oil prices have jumped almost 4% in the past month alone, while gold is up 1.6% in the same period. Sugar, cotton, corn, wheat and coffee have all hit new highs over the past two months.
Some economists are worried that these commodities will head even higher in the next few months as a result of the Fed's more aggressive policies.
Most of the so-called "consumer" commodities were sharply lower, with cocoa, sugar and coffee each sliding about 1.5%. Cotton bucked the trend, rising 1.1%.
Oil inventories: The Energy Information Administration released its weekly oil supply report earlier on Monday. The EIA said U.S. crude stockpiles rose by 2 million barrels last week.
|Overnight Avg Rate||Latest||Change||Last Week|
|30 yr fixed||3.84%||3.80%|
|15 yr fixed||3.06%||3.03%|
|30 yr refi||3.91%||3.86%|
|15 yr refi||3.16%||3.08%|
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